Scientists knew that a deadly tsunami was heading towards the coastlines of Asian nations last week. But they were unable to provide effective warnings because of a lack of disaster alert systems in the region.

Within 15 minutes of the 26 December earthquake off the coast of Indonesia, Hawaii's PacificTsunamiWarningCenter sent alerts to 26 countries. But it was a further 45 minutes before warnings were broadcast on radio and television in Thailand.

Researchers on Australia's CocosIsland also detected the tsunami, but could not reach the relevant officials in South and South-East Asian nations. According to Geoscience Australia, the country's geological research agency, better communications systems in the countries affected could have meant that warnings were delivered 15 minutes sooner in Thailand.

For Sri Lanka, whose coast was hit by the tsunami two and a half hours after the earthquake, even more time could have been bought.

Expensive technologies for the detection of tsunamis have been a low priority for governments of countries such as India, Malaysia and Thailand, as the waves are rare in the Indian Ocean, compared to their frequency in the Pacific. Nonetheless, scientists have, in the past, called for greater better preparation against the threat of tsunamis.

In June 2004, for example, specialists at the United Nations Intergovernmental Oceanographic Commission warned that the Indian Ocean faced a significant threat from tsunamis and that no warning network was in place.